December 4, 2017

Naval Group's Second Generation Fuel Cell (FC-2G) AIP Progressing

French magazine Mer et Marine (Sea and Marine in English) just over a year ago (October 7, 2016) published a very interesting article describing Naval Group's (was DCNS's) second-generation fuel cell (FC‑2G). That article is by Vincent Groizeleau at https://www.meretmarine.com/fr/content/submarines-dcns-unveils-fuel-cell-aip. Mer et Marine is a paysite with perhaps a limited number of free views of the article's many photos, diagrams and much more text. The following is a summary of a small part of the article [with straight quotes
where indicated]:

Naval Group’s Indret plant near Nantes, (in France) specialises in propulsion systems
for the French Navy and for international customer navies. Since, around 2008, a team
at Indret has worked secretly to develop a second-generation fuel cell AIP for
submarine.

Naval Group's MESMA first generation AIP, now around 25 years old, [Pete comment...MESMA is essentially a modified version of France's more used nuclear submarine propulsion system. Instead of heat from nuclear fission MESMA uses heat generated by combustion of ethanol and oxygen. The problem is that unlike nuclear the MESMA system produces inadequate power and for too little time to accommodate nuclear grade coolant or heat shielding measures. While MESMA can generate more power than other AIP technologies this is at the expense of running detectably hotter and for a shorter time than competing AIP technologies. Just 3 foreign submarines (that is 3 Pakistani Agosta-90Bs) are fitted with MESMA.]

Naval Group is therefore developing a major improvement on MESMA, which is the second-generation fuel cell technology (with the acronym reversed in
French being “FC‑2G”). In FC‑2G hydrogen is produced “[straight quote] from
standard diesel fuel by chemical re-formation. In parallel with this effort,
the group also developed a patented system to inject nitrogen into the oxygen
supply line in the same proportion as in normal air resulting in a mixture that
is far less reactive than pure oxygen. This ‘synthetic air’ is then injected
into the fuel cells where it reacts with hydrogen to produce electricity.”

[Why FC-2G is better than competing approaches]

"[straight quote] Of the fuels considered by DCNS’s AIP engineers, fuel oil offered
significant benefits over ethanol and methanol particularly in terms of safety:
“methanol vapour is toxic in the event of a leak while ethanol is flammable at
temperatures over just 13 to 14°C,” says Xavier Mesnet, a former submariner who
today heads up the group’s Marketing and Development team. But this is not fuel
oil’s only advantage. Fuel oil is easy to store and is the same as that used by
conventional diesel-alternator sets. It is also readily available all over the
world, and, “unlike hydrides, which require complex port and handling
facilities, fuel oil is easy to store, purchase and transport”."READ WHOLE MER ET MARINE ARTICLE

This 4 minute Youtube was published December 16, 2016. Presenters are Xavier Mesnet, Development and Commercial Support Director at Naval Group and Pauline Sibille, Naval Group Fuel Cell AIP Project Manager.---

See current description of FC-2G on Naval Group's website as at November 4, 2017.COMMENTIt would be interesting to know how much progress Naval Group has made since October 2016 in terms of packaging FC-2G for customer navies? - Fitted or Retrofitted?- For India's Navy for the Kalvari-class and Project-75(I)?- any interest from the RAN for Australia's Future Submarine?

6 comments:

Anonymous
said...

Diesel reformation for fuel cells has been the subject of many researches in the past 20 years. There are substantial technical challenges from coking sulfur deposition, short lifecycle on catalysts operating at 1000C, design of direct injection nozzle, etc. and I am unsure if there are enough progresses made today to move it beyond the lab and/or prototype domains.KQN

Kalvari's first refit of 2023 could see the FC-2G AIP if the technology is matured enough by then and assuming DRDO/NPOL yet again fail to keep their deadline (looks likely both PAFC AIP and bio ethanol AIP are not going to be ready anytime soon)

Pete, what do you think of a very small modular N-reactor AIP that can produce say 0.5 MW or so? should be doable given the most of the technology is available already?

On what I think of a very small modular N-reactor AIP that can produce say 0.5 MW or so? I think for countries, like India and China, that have already leapt over the financial and political hurdles sufficient to produce full powered nuclear subs then half-way "small modular N-reactor AIP" may be usefull to put into the SSKs they want to build. So small modular N-reactor AIP fills a superior SSK niche.

But for countries like Australia that has not leapt the part fixed cost nuclear establishment technical hurdles or persuaded its population that going nuclear propulsion is a good idea - then going to full nuclear first would tick more strategic boxes than small modular "half-way" N-reactor AIP.

Canada is ahead of Australia in building things nuclear, but politically on the North American continent, the US can again say "no to Canadian SSNs". Australia, in part, chose SSN capable France to avoid the US nuclear propulsion veto.

In my view, the cons of an SSK with a nuclear AIP are double the risks (since you double the systems), double expertise skill sets (dissimilar systems so you now need both nuclear engineers and diesel engineers on board), double the maintenance complexities not counting the special costs associated with future disposal and decommissioning. Since you are installing a nuclear reactor for AIP on board, you may as well make the jump to an SSN.KQN

Hey KQN, you are right about the costs (both money and manpower wise) and I agree that SSN or SSGNs offer much bigger weapon payloads, endurance etc..

The thought process has its supporters in the Indian Navy too (i.e. a shift to a all N Sub force), however considering shallower water operating environments vis a vis pakistan and also the inherent advantages of n-AIP SSK such as smaller size, maneuverability, decent ability to operate quietly etc.., it might not be a bad idea to have a SSGN-SSK combine.

the conclusion has been that a two tier sub-force, namely Nirbhay/Brahmos LACM/SLCM loaded SSGNs for the blue water navy part and SSKs for the littoral scenario has been agreed on. the PAFC AIP commercial manufacture trials (via Thermax India) and the Project 75(I) push are part of the outcome of such a thought process. the execution itself, I am afraid will be long drawn, tedious & likely capable of even enraging the Buddha into violence :(

PS: The reactor and hull design for the Indian SSN is going to be challenging considering the stresses on the SSGN hull (as opposed to the Arihant boomer), not to mention the need for the reactor to be able to rapidly ramp up & ramp down in the case of combat scenarios.The Arihant reactor will most likely not suffice. I hope an SSN reactor is in the works.

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